Study Explores Efficacy of Mistletoe Extract to Help Treat Cancer

Researchers recently completed the first phase of a study on the effect of intravenous mistletoe extract on cancer patients, documenting promising findings on the treatment’s safety as well as its effect on quality of life and disease control.

Phase I of the trial, published in Cancer Research Communications, aimed to determine the maximum doses of mistletoe extract, known as Helixor M, that could be safely tolerated by patients. The study was conducted by researchers from the John Hopkins University School of Medicine (JHUSOM) in Baltimore, Maryland, and led by Channing Paller, MD, associate professor of oncology at JHUSOM.

Labeled as a semi-parasitic plant, mistletoe has several active ingredients that have been directly linked with the death of tumor cells and a stimulated immune response. The plant’s extract is not approved for cancer treatment by the United States Food and Drug Administration (FDA), but according to the study it’s listed in the Homeopathic Pharmacopoeia and used in many integrative care clinics.

The study included 21 patients with advanced and treatment-resistant cancers of various types. Mistletoe extract was delivered intravenously three times per week until disease progression or toxicity. To determine the maximum dose to use for phase II of the study, researchers used dose escalation. They concluded that dose to be 600 milligrams.

The median follow-up time for patients was 15.3 weeks. Results showed stable disease in five patients 15 weeks after the trial. Three patients had tumors decrease in size and remained stable for two to five months, although this did not meet criteria for a partial response to the treatment. In a questionnaire, patients reported an overall improved quality of life. Side effects of the therapy included fatigue, nausea, and chills.

"Intravenous mistletoe demonstrated manageable toxicities with disease control and improved quality of life in this group of patients, who had already received multiple cancer therapies," said Paller.

According to the study’s authors, these results warrant future trials, showing promise for mistletoe extract and its efficacy as a cancer treatment.